Method of making a metallic container



Feb. 4, 1969 H. E. COLLINS ETAL 3,425,379 METHOD OF MAKING' A METALLICCONTAINER Filed Aug. 18, 1964 i i INVENTORS F; 9 HERBERT E. COLLINS FREDWARD HOLLOWAY, JR.-

THEIR ATTORNEYS United States Patent METHOD OF MAKING A METALLICCONTAINER Herbert E. Collins and Fred Ward Holloway, Jr., Richmond, Va.,assignors to Reynolds Metals Company,

Richmond, Va., a corporation of Delaware Filed Aug. 18, 1964, Ser. No.390,296

US. Cl. 113-120 14 Claims Int. Cl. B21d 51/00; B21c 9/02 ABSTRACT OF THEDISCLOSURE An aluminum-containing sheet or foil has a coating applied toboth sides thereof. The coating includes oleic acid or an ester of oleicacid. The coating can comprise a suitable solvent, such as hexane,toluol or isopropinol. The coating is applied to the sheet and thendried as by passing able solvent, such as hexane, toluol or isopropanol.The coated sheet can then be placed in a forming die to draw it into areceptacle or the like. The coated sheet resists rupturing in the diebecause of its coating. A cover may be sealed to the flange of thereceptacle and the coating enhances the sealing characteristics of theflange. The cover may be an aluminum containing foil or sheet with apolyethylene layer to be heat sealed to the flange.

This invention relates to an improved metallic part or the like as wellas to an improved method of making such part or the like.

It is well known that metallic receptacles for food and the like can beformed by drawing a sheet of aluminumcontaining foil or the like into anopen ended compartmentalized receptacle having a surrounding horizontalflange to which a cover member can be hermetically sealed by aninterposed layer of heat sealing material carried by the cover memberwhereby the food product inside the receptacle is hermetically sealedtherein.

However, it has been found that such hermetically sealed receptacleswill not withstand ordinary abuse because a relatively weak heat sealedbond exists between the receptacle and its cover whereby flavor loss andproduct spoilage results.

Further, it is well known that when such a sheet of metallic foil or thelike is drawn into the aforementioned compartmentalized open endedreceptacle, some means must be utilized to provide lubrication betweenthe sheet of material and the die forming means so as to prevent ruptureof the relatively thin sheet of metallic foil during the drawingoperation.

In the past, receptacle manufacturers have coated the sheets of metallicfoil with stearic acid in order to provide the necessary lubricationbetween the sheet of material and the forming dies. However, it has beenfound that when such treated foil receptacles are thereafter utilized incombination with a heat scalable lid or the like, the heat sealresulting therebetween is relatively weak and provides an inferiorfinished product.

According to the teachings of this invention, an improved coating forthe metallic foil is provided whereby not only does the coating providelubrication means between the sheet of material and the forming dies soas to prevent rupture of the sheet of material during its subsequentdrawing operation, but also the coating of this invention enhances theadhesive properties between the receptacle and the cover thereforwhether the cover is heat sealed thereto or secured by other adhesive asdesired.

In addition, it has been found that the coating of this invention tendsto render the sheet of material corrosive resistant.

Accordingly, it is an object of this invention to provide improvedmetallic container part or the like having one 3,425,379 Patented Feb.4, 1969 "ice or more of the novel features of this invention as setforth above or hereinafter shown or described.

Another object of this invention is to provide an improved method forforming such a container part or the like, the method of this inventionhaving one or more of the novel features set forth above or hereinaftershown or described.

Other objects, uses and advantages of this invention are apparent from areading of this description which proceeds with reference to theaccompanying drawings forming a part thereof and wherein:

FIGURE 1 is a perspective view illustrating metallic foil stock in rollform.

FIGURE 2 is a perspective view illustrating foil stock in sheet form.

FIGURE 3 is a schematic, cross-sectional view illustrating one method ofapplying the coating of this invention to the metallic material ofFIGURE 1 or 2.

FIGURE 4 is a schematic side view illustrating one method for drying thecoating which has been applied to the sheet of material in the mannerillustrated in FIG- URE 3.

FIGURE 5 is a schematic side view and illustrates the coated sheet ofmaterial in a forming press that forms the sheet of material into anopen ended compartmentalized receptacle.

FIGURE 6 is a perspective top view illustrating the formed receptacle ofthis invention.

FIGURE 7 is a fragmentary, cross-sectional, perspective view of oneembodiment of the cover member of this invention.

FIGUIU-E 8 is an axial cross-sectional view of the improved container ofthis invention formed from the receptacle of FIGURE 6 and the covermember of FIG- URE 7.

FIGURE 9 is a cross-sectional view of a container body formed from aplurality of plies in a spirally wound manner or convolntely woundmanner as desired.

FIGURE 10 is an enlarged, fragmenary cross-sectional view illustratingthe container body of FIGURE 9 joined to a container lid or the like.

While the various features of this invention are here inafter describedand illustrated in connection with metallic foil being utilized to formcontainer parts, it is to be understood that the various features ofthis invention can be utilized singly or in any combination thereof toimprove other objects or the like.

Therefore, this invention is not to be limited to only the embodimentsillustrated in the drawings, because the drawings are merely utilized toillustrate one of the wide variety of uses of this invention.

Referring now to FIGURES 1 and 2, the metallic foil stock, such asaluminum-containing metallic foil or the like, can be supplied in rollform as indicated by the reference numeral 20 in FIGURE 1 or in sheetform as indicated by the reference numeral 20 in FIGURE 2.

In either event, the metallic foil 20 is adapted to have a coating ofthis invention applied on the opposed sides thereof in any suitablemanner such as by spraying, dip ping, roller application, reverserolling application, gravure cylinder rolling, or other means ofmetering the application of the coating thereon.

For example, reference is made to FIGURE 3 of this invention wherein thecoating 21 of this invention is contained in a receptacle 22 and themetallic foil 20 is first passed through the coating 21 and then througha nip of a pair of rollers 23 so as to properly meter the amount ofcoating 21 thereon. In this manner, the coating 21 is applied to bothsides of the sheet of metallic foil 20 to permit the metallic foil 20 tohave improved characteristics for a purpose hereinafter described.

It has been found according to the teachings of this invention, that ifthe coating 21 includes oleic acid or an ester of oleic acid, theresulting coating 21 on the sheet of material 20 will readily permit thesheet of material to be drawn into a receptacle form or the like withouta rupturing thereof because the coating provides a lubrication meansbetween the sheet of material 20 and the forming die means, the coating2.1 also readily permitting the formed sheet of material 20 to beadhesively secured to other structure or the like and also rendering thesheet of material 20 substantially corrosive resistant.

For example, the coating 21 can comprise about 2% by weight of glycerolmonooleate in about 98% by weight of a suitable solvent, such as hexane,toluol or isopropyanol, whereby the coating applied to the sheet ofmaterial 20 in the manner illustrated in FIGURE 3 can be subsequentlydried by passing the same through oven drying means 24 in FIGURE 4wherein the solvent is evaporated and the ester of oleic acid is set upon the sheet of material 20.

The glycerol monooleate is available under the trade name of GlycerolMonooleate O of the Chemical Division of the Armour Industrial ChemicalCompany, Chicago, Ill.

Another coating containing oleic acid is available under the trade nameof Hamidraw No. 30l-2B-FDA from the Harry Miller Corporation ofPhiladelphia, Pa.

After the coated sheet of material 20 has the coating 21 dried thereonby the oven means 24, the coated sheet of material 20 can be placed in aconventional forming die means 25 in the manner illustrated in FIGUREwherein the sheet of material can be drawn into a receptacle 26comprising a compartmentalized structure having an outer surroundingfiat horizontal flange 27, the coated sheet of material 20 not rupturingin the die means because the coating 21 acts as a lubricating meansbetween the sheet of material 20 and the forming dies 25 to prevent suchrupturing.

Thereafter, a suitable cover member 23 can be hermetically sealed to thehorizontal flange 27 of the receptacle 26 by any suitable adhesive meansto hermetically seal desired products in the receptacle 26.

For example, the cover member 28 illustrated in the drawings comprises asheet of metallic foil 29 having a film 30 of polyethylene laminatedthereto. Such cover member 28 is adapted to be placed over the filledreceptacle 26 in the manner illustrated in FIGURE 8 and have its outerperipheral portion 31 heat sealed to the peripheral flange 27 wherebythe heat sealable polyethylene 30 hermetically seals the cover member 28to the filled receptacle 26, the coating 21 on the formed receptacle 26enhancing the heat sealing of the cover member 28 to the receptacle 26.

While the cover member 28 has been previously described as being securedto the horizontal flange 27 of the receptacle 26 by a heat sealing means30, it is to be understood that the coating 21 of this invention is alsoreadily adaptable to permit other types of adhesives to secure the covermember 28 thereto.

However, in one example of this invention, it has been found that thereceptacle 26 can be made from aluminum-containing metallic foil havinga thickness of approximately 0.0045 of an inch thick and that the covermember 28 can be made from a layer 29 of aluminumcontaining metallicfoil of approximately 0.00035 of an inch thick with the polyethylenelayer 30 being approximately 1% mils thick.

The coating 21 being applied to such a sheet 20 of metallic foil can bein a range from 0.02 to 0.08 lb. per ream of foil 20.

For example, it has been found that when the coating 21 is formed from1% by weight of the aforementioned Harry Miller composition and 1% byweight of the Armour Industrial Chemical Company composition in a 98% byweight hexane solvent, the following results were obtained.

It was found that by coating a sheet of material 20 with the coating 21in the above manner, and, after drying the coating, another sheet ofmaterial could be heat sealed thereto with different heating headtemperatures, pressures and time of dwell with the following results:

Heating head Pressure applied Dwell of Pounds per temperature by heatinghead heating head square inch in degrees in p.s.i. in seconds that heatseal resisted 20 z, 1. 62 20 1 2. 05 30 5 1. 91 30 1 2. 37 40 2. 03 40 12. 26 20 1'5 1. 85 20 1 2. 27 30 V 1. 30 1 2. 59 40 l5 2. 08 40 1 2. 4220 5 2. 15 20 I 2. 44 30 $6 2. 38 30 1 2. 64 40 i6 2. 66 40 1 2. 74 20 y2. 31 20 1 2. 54 30 5 5 2.33 30 1 2. 74 40 2. 44 40 1 2. 67

When utilizing only the Harry Miller composition together with a toluolsolvent, the following results were obtained when the heat sealing headhad a temperature of 350 F., an applying pressure of 40 p.s.i. and witha 1 second heat seal dwell.

When the Harry Miller composition was 1% by weight of the coating 21,the resultant heat seal withstood 1.96 lbs. per square inch; when theHarry Miller composition was 1.5% by weight of the coating 21, theresulting heat seal withstood a pressure of 2.59 lbs. per sq. inch; whenthe Harry Miller composition was 2% by weight of the coating 21, theresulting heat seal withstood 1.62 lbs. per sq. inch; and when the HarryMiller composition was 2.5% by weight of the coating 21, the resultingheat seal withstood 1.13 lbs. per sq. inch.

Therefore, it can be seen that by utilizing a coating containing anester of oleic acid, a sheet of metallic foil is readily adapted to beformed into the desired shape without rupture thereof, be readilyadhesively secured to other structures and will be substantiallycorrosive resistant.

While the various features of this invention have been described abovein connection with food receptacles of the general type illustrated inFIGURE 6, it is to be understood that the various features of thisinvention can be utilized with other containers or the like.

For example, reference is made to FIGURE 9 wherein a container body 32is provided and comprises an inner lining 33 of metallic foil or thelike, an outer label or wrapper 34 of metallic foil or the like and aninterposed layer 35 of cardboard or the like, the container body 32being formed by convolutely winding the layers 33-35 or spirally windingthe same in the manner conventional in the art.

As illustrated in FIGURE 10, it can be seen that the container body 32subsequently has the outer end 33 thereof simultaneously formedoutwardly and joined to a curled flange 37 of a metallic cover member 38in a conventional cover sealing manner. However, when the cover member38 does not have the coating 21 of this invention thereon, it has beenfound that the lining 33 is more than likely to rupture during the canend sealing operation whereby adverse leaking subsequently results. Byutilizing the coating 21 of this invention, the end 36 of the containerbody 32 is adapted to be readily formed to accept the can end closure 38without rupture thereof because of the lubricating properties of thecoating 21 which readily permits the foil of the container body 32 to beso formed. Further, if a sealant is utilized between the body 32 and endclosure 38, the coating 21 promotes the sealing therebetween.

If desired, the foil lining 33 and wrapper 34 could also be coated withthe coating 21 of this invention.

Therefore, it can be seen that not only does this invention provide animproved container or the like but also this invention provides improvedparts for such a container or the like.

In addition, it can be seen that the various features of this inventionare readily adaptable for improving the characteristics of othermetallic objects or the like whereby this invention is not to be limitedto any particular structure or use thereof.

While the form of the invention now preferred has been disclosed asrequired by the statutes, other forms may be used, all coming within thescope of the claims which follow.

What is claimed is:

1. A method for forming a metallic member comprising the steps ofcoating said member with one of the group consisting of oleic acid andan ester of oleic acid, and forming said member into the desiredconfiguration with forming means whereby said coating prevents ruptureof said member by said forming means by acting as a lubricanttherebetween.

2. A method for forming metallic foil or the like comprising the stepsof coating said foil with one of the group consisting of oleic acid andan ester of oleic acid, and forming said foil into the desiredconfiguration with forming means whereby said coating prevents ruptureof said foil by said forming means by acting as a lubricanttherebetween.

3. A method as set forth in claim 2 wherein said ester of said groupcomprises glycerol monooleate.

4. A method as set forth in claim 2 wherein said ester of said group isdisposed in a solvent.

5. A method as set forth in claim 4 wherein said solvent is one of thegroup consisting of hexane, toluol and isopropanol.

6. A method as set forth in claim 4 and including the step ofevaporating said solvent before forming said foil.

7. A method for making an object comprising the steps of coating ametallic member with one of the group consisting of oleic acid and anester of oleic acid, forming said member into the desired configurationwith forming means whereby said coating prevents rupture of said memberby said forming means by acting as a lubricant therebetween, andsecuring another member to coated part of said metallic member with aninterposed adhesive means.

8. A method for making a container or the like comprising the steps ofcoating a sheet of metallic foil with one of the group consisting ofoleic acid and an ester of oleic acid, forming said sheet into thedesired container part with forming means whereby said coating preventsrupture of said foil by said forming means by acting as a lubricanttherebetween, and heat sealing another container part to a coatedportion of said first-named contaizer part whereby said coating enhancesthe heat seal securement between said container parts.

9. A method as set forth in claim 8 and including the step of providingpolyolefin on said other container part to form said heat sealing means.

10. A method as set forth in claim 8 wherein said ester of said groupcomprises glycerol monooleate.

11. A method as set forth in claim 8 wherein said ester of said group isdisposed in a solvent.

12. A method as set forth in claim 11 wherein said solvent is one of thegroup consisting of hexane, toluol and isopropanol.

13. A method as set forth in claim 11 and including the step ofevaporating said solvent before forming said sheet.

14. A method for enhancing the characteristics of a metallic membercomprising the step of coating said metallic member with one of thegroup consisting of oleic acid and an ester of oleic acid.

References Cited UNITED STATES PATENTS 1,890,193 12/ 1932 Punte 1l3-1212,047,076 7/ 1936 Kronquest 113121 1,908,601 5/1933 Gridley 1563263,054,703 9/1962 Brasure 161-214 3,040,781 6/1962 Reymann et al 113-1203,194,428 7/1965 Dereich 113-120 RONALD D. GREFE, Primary Examiner.

